Method and apparatus for communications in a wellbore

Abstract

A downhole string includes a system having an actuator module that is responsive to electrical power and signals communicated down a cable, such as a permanent downhole cable (PDC). In addition, a backup mechanism, such as an inductive coupler mechanism or another type of wireless apparatus, can be used as a backup to restore power and communications with the downhole system. For example, if the cable fails for some reason, power and signals can still be communicated with the inductive coupler mechanism or other wireless mechanism to control operation of the system or to receive signals from the system.

What is claimed is:  
     
       1. A method of communications in a wellbore, comprising: 
       determining if a first communications mechanism for communicating with a downhole device is operational;  
       running a backup communications mechanism into the wellbore in response to determining that the first communications mechanism is not operational; and  
       communicating with the downhole device using the backup communications mechanism.  
     
     
       2. The method of  claim 1 , wherein running the backup communications mechanism into the wellbore is performed after determining that the first communications mechanism is not operational. 
     
     
       3. The method of  claim 1 , wherein determining if the first communications mechanism is operational comprises determining if an electrical cable is operational. 
     
     
       4. The method of  claim 3 , wherein running the backup communications mechanism comprises running at least a first portion of an inductive coupler mechanism into the wellbore. 
     
     
       5. The method of  claim 1 , wherein providing the secondary, wireless communications link comprise providing a first portion of an inductive coupler coupled to the well device. 
     
     
       6. The method of  claim 5 , further comprising running a second portion of an inductive coupler device into the well into functional alignment with the first portion. 
     
     
       7. The method of  claim 1 , wherein running the backup communications mechanism comprises running a wireless apparatus. 
     
     
       8. The method of  claim 7  wherein running the wireless apparatus comprises running an inductive coupler element. 
     
     
       9. The method of  claim 7  wherein determining if the first communications mechanism is operational comprises determining if an electrical cable is operational. 
     
     
       10. The method of  claim 7 , further comprising positioning a first element of the wireless apparatus downhole, wherein running the wireless apparatus comprises running a second element of the wireless apparatus proximal the first element. 
     
     
       11. The method of  claim 10 , wherein positioning the first element comprises positioning a first inductive coupler element and running the second element comprises running a second inductive coupler element. 
     
     
       12. A method of communications in a well, comprising: 
       providing a primary communications link from a well surface to a well device; and  
       providing a secondary, wireless communications link from the well surface to the well device.  
     
     
       13. The method of  claim 12 , wherein providing the secondary, wireless communications link comprise providing a link for carrying one of electromagnetic signals, pressure pulse signals, acoustical signals, and optical signals. 
     
     
       14. The method of  claim 9 , wherein inserting the secondary, wireless communications link comprises running an inductive coupler portion into the well after determining that the primary communications link is not operational. 
     
     
       15. An apparatus for use in a wellbore, comprising: 
       a first communications link adapted to extend from a well surface to a downhole device; and  
       a redundant link adapted to extend from the well surface to the downhole device, the redundant link comprising a wireless apparatus.  
     
     
       16. The apparatus of  claim 15 , wherein the first communications link comprises an electrical line. 
     
     
       17. The apparatus of  claim 13 , wherein the redundant link comprises an inductive coupler portion adapted to be run into the wellbore after detection of the first communications link being in-operational. 
     
     
       18. The apparatus of  claim 15 , wherein the wireless apparatus comprises an inductive coupler mechanism. 
     
     
       19. The apparatus of  claim 18 , wherein the inductive coupler mechanism comprises a female coil electrically coupled to the downhole device and a male coil for running into the wellbore. 
     
     
       20. The apparatus of  claim 18 , wherein the inductive coupler mechanism comprises a first part positioned in the wellbore and a second part adapted to be lowered into and removed from the wellbore. 
     
     
       21. The apparatus of  claim 20 , further comprising a downhole component defining a chamber, the first part being enclosed in the chamber. 
     
     
       22. The apparatus of  claim 21 , wherein the downhole component comprises a housing and a protective layer attached to the housing. 
     
     
       23. The apparatus of  claim 22 , wherein the protective layer is formed of a material that exhibits relatively low electrical conductivity and that is impervious to corrosive gases and liquids. 
     
     
       24. The apparatus of  claim 23 , wherein the protective layer material is selected from the group consisting of nickel, titanium, chrome, stainless steel, a nichrome alloy, glass, and ceramic. 
     
     
       25. The apparatus of  claim 23 , wherein the protective layer material is selected from the group consisting of nickel, titanium, chrome, stainless steel, and a nichrome alloy. 
     
     
       26. The apparatus of  claim 23 , wherein the protective layer material is selected from the group consisting of glass and ceramic. 
     
     
       27. The apparatus of  claim 23 , wherein the protective layer is formed of a non-magnetic material. 
     
     
       28. The apparatus of  claim 23 , wherein the protective layer is formed of a non-corrosive material. 
     
     
       29. The apparatus of  claim 23 , wherein the downhole component further comprises a substrate, the protective layer formed on the substrate. 
     
     
       30. The apparatus of  claim 29 , wherein the substrate is formed of polymer. 
     
     
       31. The apparatus of  claim 29 , wherein the substrate is formed of polyetheretherketone. 
     
     
       32. The apparatus of  claim 23 , wherein the protective layer covers the chamber to prevent entry of corrosive gases and liquids. 
     
     
       33. The apparatus of  claim 32 , wherein the protective layer is sealingly attached to the housing to cover the chamber. 
     
     
       34. A communication system for use in a well, comprising: 
       a downhole device in the well;  
       a first communication link connected to the downhole device;  
       a redundant link connected to the downhole device, the redundant link comprising a first portion of a wireless device;  
       a second portion of the redundant link adapted for selective placement in the well for selective communication with the first portion.  
     
     
       35. The system of  claim 34 , wherein the first communication link comprises an electrical conductor adapted to extend from a well surface to the downhole device. 
     
     
       36. The system of  claim 34 , wherein the redundant link comprises an inductive coupler. 
     
     
       37. A method of operating a multilateral well having a main bore and a lateral branch, comprising: 
       lowering a wireless apparatus into the main bore;  
       engaging a downhole element to cause deflection of the wireless apparatus toward the lateral branch; and  
       running the wireless apparatus into the lateral branch to electrically couple the wireless apparatus with a downhole device in the lateral branch.  
     
     
       38. The method of  claim 37 , wherein lowering the wireless apparatus comprises lowering a first portion of an inductive coupler. 
     
     
       39. Them method of  claim 38 , further comprising: 
       providing a second portion of the inductive coupler in the lateral branch; and  
       positioning the first portion proximal the second portion for functional engagement of the first and second portions.  
     
     
       40. The method of  claim 37 , wherein engaging the downhole element comprises engaging a deflecting device. 
     
     
       41. A system for use in a well having a lateral branch, comprising: 
       a wireless apparatus having a first portion positioned in the lateral branch and a second portion adapted to be run in the well; and  
       a downhole element adapted to deflect the second portion toward the lateral branch to enable running the second portion into the lateral branch for functional engagement with the first portion.  
     
     
       42. The system of  claim 41 , wherein the wireless apparatus comprises an inductive coupler. 
     
     
       43. The system of  claim 41 , wherein the downhole element comprises a deflecting tool. 
     
     
       44. The system of  claim 41 , wherein the downhole element comprises an anchor with a diverting surface.